crusting

A 26-year-old male with a past medical history of eczema presented to the Emergency Department with a rash for two days. The patient stated he first noticed a rash on his right arm that rapidly spread to his face, chest, and left arm. He reported having similar rashes before but never to this extent. The patient stated he was given Bactrim and amoxicillin about one month ago for another rash, though he was unsure of the diagnosis. He denied any known allergies or exposures to new foods or hygiene products. He had no chest pain, SOB, nausea, or diarrhea. He lives in a correctional facility and does not know of anyone with any rashes.

Vitals: Temp 102.7°F; BP 134/81; HR 137; RR 17; O2 100% on room air

Cardiac: Tachycardic, no murmurs

Lungs: CTABL

Skin: Pustular vesicles with scattered areas of confluency on face, upper extremities and torso. Yellow crusting on face, no mucosal involvement.

WBC: 17

Platelets: 261

Blood cultures: One of two positive

CMP and UA WNL

Non-bullous Impetigo

Impetigo is a rash that effects the epidermis. There are two main types, bullous and non-bullous. S. Aureus and S. Pyogenes are the most common causes of non-bullous impetigo with S. Aureus accounting for up to 80% of cases. Impetigo is highly contagious and patients often self-inoculate other areas of their skin after the initial lesion develops. As papules develop, they fill with pus and once ruptured a classically characterized honey-colored crust is left on the skin. It is more common in immunocompromised patients, diabetics, patients with poor hygiene, and those patients who spend time in crowded dwellings such as daycare or prison. Systemic antibiotics are recommended in all cases of bullous impetigo and in non-bullous impetigo if there are more than five lesions, signs of deeper tissue involvement, or systemic symptoms as was the case with this patient. Beta-lactamase-resistant antibiotics such as Keflex or Augmentin are often the first line and if the patient resides in an area with a high prevalence of MRSA, doxycycline or clindamycin are recommended. Once diagnosed, it is important to wash any clothing, bedding, or infected surfaces to prevent further household or community spread. In the case of this patient, he developed systemic symptoms ultimately becoming septic, and required admission with IV antibiotics. He made a full recovery.

Take-Home Points

  • Suspect in patients who are immunocompromised or have contact with crowded dwellings such as daycare or jail.
  • The classic skin finding is a honey-colored crust.
  • Patients with systemic symptoms or more than five lesions need systemic antibiotics.

  • Nardi NM, Schaefer TJ. Impetigo. [Updated 2023 Jul 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https:// www.ncbi.nlm.nih.gov/books/NBK430974/
  • Group A Strep Infection. (n.d.). Group a Strep Infection. https://www.cdc.gov/group-a-strep/?CDC_AAref_Val=https://www.cdc.gov/groupastrep/diseases-%2520hcp/impetigo.html

Melissa Smith, MD

Melissa Smith, MD

Assistant Professor
APD
UT Southwestern Medical Center

Paris Price, MD

Resident Physician
UT Southwestern Medical Center

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